1. Field of the Invention
The present invention relates to a hypodermic syringe and more particularly, to a safety hypodermic syringe, which prevents contamination after its service and, which is inexpensive to manufacture.
2. Description of the Related Art
U.S. Pat. No. 6,423,033 B1, issued to the present inventor, discloses a safety hypodermic syringe in which a pull handle is inserted into the plunger and adapted to pull the needle assembly backwards to the inside of the plunger in the barrel after the service of the safety hypodermic syringe. The pull handle has a middle neck through which the rear part of the pull handle can easily be separated from the front part of the pull handle by bending, enabling the separated rear part of the pull handle to be inserted into the plunger in the barrel and hooked up with the front part of the pull handle.
The aforesaid safety hypodermic syringe is functional, however the arrangement of the plunger and the pull handle complicates the structure, resulting in a high manufacturing cost.